Light and dark

Songs work when they are balanced; when they contain similar amounts of light and dark or opposites or when they cover different areas of the sonic spectrum. Whether you're writing a Phil Spector wall-of-sound piece jammed up with every sound you can think of or a spartan slowcore track with 4 simple elements, I think the principle is a good one. A good question to consider when writing or arranging is whether or not an additional instrument or sound is covering a new part of territory or occupying that already occupied by another.

I was listening to Breaker by Low (which definitely belongs in the latter category). Low seem to be one of these bands which do this kind of thing well. This particular song begins with a quietish beat and eventually a doubled hand clap. Later, vocals and a couple of other instruments kick in. These elements reflect the light-and-dark idea.

The beat is low-end, electronic, complex, the hand-clap by contrast is higher and brittle, human and simple. The organ chords sit on a layer above the beat and differs from it by being polyphonic rather than monophonic. They also move from major to minor. The vocals themselves are composed of opposites or distinct differences: man/woman, high/low, melody/harmony. One of the final sounds added, a warbly backwards guitar feedback kinda thing acts as a disruptor or mediator to the neat discrete sections by being none of these; it's organic and electronic, it's high and low, it falls in and out of patterns, sometimes you hear one note, sometimes a few.

This is an example of light and dark happening vertically, or in the song's layers of sound. But it's also good for songs to have light and dark horizontally, meaning as the song progresses through time. Different sections should do opposite or different things: the verse is quieter than the chorus; few instruments begin, many finish, the chorus is simple, the verse complex and so on.